The adventures of smart soldier Gustav Diestelbeck include managing his superior officer, competing for the canteneer's daughter, evading punishment for discipline faults and hosting Prinz Willibald during his visit to the regiment.

Based on Agatha Christie's "The Secret Adversary," a young couple looking for adventure become involved in the mystery of a missing woman and an espionage ring.

During a railway journey, Baron van Geldern meets Evelyne, an attractive young woman travelling in the same carriage. After the train is derailed, they spend a night together at a hotel, and the womanizer falls in love with her. Complications ensue when he discovers that she is engaged to his American friend.